Public demand for protein therapeutics is increasing dramatically and soon will exceed the processing capacity using existing systems - the so-called 'capacity crunch'. There is enormous pressure to identify and employ a high-throughput and high-resolution recovery and purification method that will enable the cost-effective production of the projected large masses of protein therapeutics needed in the near term. This same rapid protein recovery and purification process would be of tremendous value as an analytical technology to provide highly purified proteins for basic health-related research. Membrane chromatography has emerged as a high-throughput alternative to conventional resin column chromatography for protein purification. Yet, broad implementation of membrane chromatography in initial protein capture steps has been slow because membrane absorbers have had lower per volume protein binding capacities than resin columns. One objective of this research program is to turn high capacity into an advantage for membranes by grafting high-capacity polymer nanolayers from base membrane supports. A goal is to understand the roles of nanolayer structure, membrane pore structure, and novel polymer chemistry on protein binding, with the major objective to accelerate the use of membrane chromatography in initial protein capture steps, whether these are based on cation exchange or affinity interactions. Protein capture steps often employ affinity separation media. When the affinity ligand is a protein, the separation media becomes a major cost center for the entire purification process. Thus, low-cost synthetic affinity ligands have tremendous potential to lower purification costs for protein therapeutics produced by cell culture technology, both at the laboratory scale and at large scale. A second major objective of this research program is to use synthetic polymer chemistry to prepare high-selectivity, high-productivity affinity membranes. A modular design approach will be used to prepare affinity membranes for protein-specific purifications. Emphasis will be given to the development of affinity membranes for the isolation and purification of cell- penetrating proteins used for facilitated intracellular delivery of therapeutic agents. PUBLIC HEALTH RELEVANCE: This research program will deliver high-performance membranes for chromatography based protein purifications. The rapidly growing public demand for protein therapeutic products requires new, higher productivity, higher resolution methods for their recovery and purification. Development of these materials is essential to the production of lower cost therapeutic products for improved public health, as well as the isolation and purification of cell-penetrating proteins for facilitated intracellular delivery of therapeutic agents.